Light source for plant cultivation

ABSTRACT

A plant cultivation light module includes a first light source, a second light source, and a controller. The first light source includes a first light emitter configured to emit first light having peak wavelength in a visible range and second light emitter configured to emit second light having a longer peak wavelength to the first light. The second light source includes a plurality of third light emitters configured to emit third light having a shorter peak wavelength to the first light. The controller is configured to control the first light emitter, the second light emitter and the plurality of third light emitters and provide a first light pattern and a second light pattern. The first light source supplies light of the first light pattern and the second light source supplies light of the second pattern to the plant, respectively.

CROSS-REFERENCE TO RELATED APPLICATION

The Present Application is a continuation of U.S. application Ser. No.16/548,350 filed Aug. 22, 2019 which claims the benefit of U.S.Provisional Application No. 62/722,405, filed on Aug. 24, 2018, which ishereby incorporated by reference for all purposes as if fully set forthherein.

BACKGROUND 1. Field of Disclosure

The present disclosure relates to a light source for plant cultivation.More particularly, the present disclosure relates to a light source thatemits a light resulting in increasing a content of active ingredient inAsteraceae family plants.

2. Description of the Related Art

Various light sources, as an alternative to sunlight are underdevelopment and have been used as lightings for plant cultivation.Conventionally, incandescent lamps and fluorescent lamps are mainly usedas the lighting sources for plant cultivation. However, the conventionallightings for plant cultivation provide light having a specificwavelength to plants for only the purpose of plant photosynthesis, andmost of them may not have additional functions.

Plants synthesize substances useful to humans while resisting a varietyof stress factors, and to this end, a light source and a cultivationdevice are required to cultivate plants that contain a large amount ofsubstances useful to humans.

SUMMARY

According to one or more embodiments of the present disclosure, a plantcultivation light module includes a first light source, a second lightsource and a controller. The first light source includes a first lightemitter configured to emit first light having peak wavelength in avisible range and a second light emitter configured to emit second lighthaving a longer peak wavelength to the first light. The second lightsource includes a plurality of third light emitters configured to emitthird light having a shorter peak wavelength to the first light. Thecontroller is configured to control the first light emitter, the secondlight emitter and one or more of the plurality of third light emitterssuch that a first light pattern and a second light pattern aregenerated. The first light source and the second light source furtherinclude a first semiconductor layer, a second semiconductor layer, andan active layer. The active layer is disposed on the first semiconductorlayer to emit a light having a specific wavelength due to a band gapdifference in an energy band depending on a material used to form theactive layer. The first light pattern provides a first light spectrumand the second light pattern provides a second light spectrum having atleast one more peak wavelength than the first light spectrum. The firstlight source supplies, to the plant, light of the first light patternand the second light source supplies, to the plant, light of the secondpattern.

In at least one variant, the first light source comprises a plurality offirst light emitters and a plurality of second light emitters, and acomposition ratio of the plurality of first light emitters and theplurality of second light emitters differ.

In another variant, the second light emitter is further configured toemit light in an infrared wavelength band or near-infrared wavelengthband.

In another variant, the plurality of third light emitters is furtherconfigured to emit light of an ultraviolet wavelength band.

In another variant, the controller controls the first light source andthe second light source individually.

In another variant, the plurality of third light emitter is furtherconfigured to emit the third light having a sharp peak at a specificwavelength having a narrower FWHM than a UV lamp thereof.

In another variant, the controller controls operations of the firstlight source and second light source wirelessly.

In another variant, the plurality of third light emitters is configuredto provide to the plant the third light correlated to increase a contentof an active ingredient in the plant. The active ingredient comprises atleast one of chlorophylls, flavonoids, anthocyanins, chlorogenic acids,sesquiterpene lactones, and phenolic compounds.

In another variant, the first light source comprises a plurality offirst light emitters and a plurality of second light emitters. Acomposition ratio of the plurality of first light emitters and theplurality of second light emitters is identical and the plurality offirst light emitters and the plurality of second light emitters aredriven at different ratios depending on a type of the plant.

According to one or more embodiments of the present disclosure, a plantcultivation device includes a main body housing a plant, a light sourceprovided in the main body to irradiate a light to the plant, and acontroller controlling the light source. The light source includes afirst light source and a second light source. The first light sourceincludes a first light emitter configured to emit first light havingpeak wavelength in a visible range and a second light emitter configuredto emit second light having a longer peak wavelength to the first lightemitter. The second light source includes a plurality of third lightemitters configured to emit third light having a shorter peak wavelengthto the first light emitter. The controller is configured to control thefirst light emitter, the second light emitter, and the plurality ofthird light emitters such that a first light pattern and a second lightpattern are provided. The first light source and the second light sourcefurther include a first semiconductor layer, a second semiconductorlayer, and an active layer. The active layer is disposed on the firstsemiconductor layer to emit a light having a specific wavelength due toa band gap difference in an energy band depending on a material used toform the active layer. The first light pattern provides a first spectrumand the second light pattern provides a second spectrum having at leastone more peak wavelength than the first spectrum. The first light sourcesupplies, to the plant, light of the first light pattern and the secondlight source supplies, to the plant, light of the second light pattern.

In at least one variant, the first light source comprises a plurality ofthe first light emitters and a plurality of second light emitters, and acomposition ratio of the plurality of first light emitters and theplurality of second light emitters differ.

In another variant, the controller controls the first light source andthe second light source individually.

In another variant, the controller controls operation of the first lightsource and second light source wirelessly.

In another variant, the plurality of third light emitters is furtherconfigured to provide to the plant the third light correlated toincrease a content of an active ingredient in the plant, wherein theactive ingredient comprises at least one of chlorophylls, flavonoids,anthocyanins, chlorogenic acids, sesquiterpene lactones, and phenoliccompounds.

In another variant, the controller is further configured to control thefirst light emitter, the second light emitter, and the plurality ofthird light emitters such that the light of the first light pattern iscustomized to a type of seeds of the plant.

According to one or more embodiments of the present disclosure, a plantcultivation light module includes a first light source, a second lightsource, and a controller. The first light source includes a plurality offirst light emitters configured to emit first light and a plurality ofsecond light emitters configured to emit second light having a longerpeak wavelength than the first light. The second light source includes aplurality of third light emitters configured to emit third light havinga shorter peak wavelength to the first light. The controller isconfigured to control the plurality of first light emitters, theplurality of second light emitters, and the plurality of third lightemitters such that a first light pattern and a second light pattern areprovided. The first light source and the second light source furthercomprise a first semiconductor layer, a second semiconductor layer, andan active layer. The active layer is disposed on the first semiconductorlayer to emit a light having a specific wavelength due to a band gapdifference in an energy band depending on a material used to form theactive layer. The first light pattern provides a first spectrum and thesecond light pattern provides a second spectrum having at least one morepeak wavelength than the first spectrum. A composition ratio of theplurality of first light emitters and the plurality of second lightemitters differ.

In at least one variant, the controller controls the first light sourceand the second light source individually.

In another variant, the controller controls operation of the first lightsource and second light source wirelessly.

In another variant, the plurality of third light emitters provides tothe plant the third light correlated to increase a content of an activeingredient in the plant. The active ingredient comprises at least one ofchlorophylls, flavonoids, anthocyanins, chlorogenic acids, sesquiterpenelactones, and phenolic compounds.

In another variant, the composition ratio is adjusted such that thefirst light pattern, the second light pattern or both are customized toa type of the plant.

The present disclosure provides a light source for emitting a light thatincreases a content of an active ingredient while retaining an inherentcolor of Asteraceae family plants.

Embodiments of the inventive concept provide a plant cultivation lightsource being turned on or turned off depending on a light period and adark period of a plant. The plant cultivation light source includes afirst semiconductor layer, a second semiconductor layer, and an activelayer, and the active layer is disposed on the first semiconductor layerto emit a light having a specific wavelength due to a band gapdifference in an energy band depending on a material used to form theactive layer. When a portion of the light period is referred to as afirst period and the other portion of the light period is referred to asa second period, the first period and the second period are alternatelyprovided with each other, and lights having different wavelengths fromeach other are provided to the plant in the first and second periods,thereby increasing a content of an active ingredient in the plant.

The cultivation light source includes a first light source emitting afirst light and a second light source emitting a second light, and oneof the first and second light sources is turned on in at least oneperiod of the first and second periods.

The second light is provided to the plant in an on and off manner.

The first light is a light of a visible light wavelength band, thesecond light is a light of an ultraviolet light wavelength band, thefirst light is provided to the plant in the first period, and the secondlight is provided to the plant in the second period.

The second light is an ultraviolet B wavelength band.

The second light has a wavelength band from about 280 nm to about 315nm.

A total cumulative energy amount of the second light irradiated to theplant is equal to or smaller than about 2.304 kJ/m².

The first period and the second period are alternately repeated in thelight period, and the first period and the second period, which areadjacent to each other, form one repetition period.

A light provided in the second period of the repetition period is notprovided in the first period.

The second period is provided in the light period from a predeterminednumber of days prior to harvest until the harvest.

The active ingredient includes at least one of chlorophylls, flavonoids,anthocyanins, chlorogenic acids, sesquiterpene lactones, and phenoliccompounds.

Embodiments of the inventive concept provide a plant cultivation deviceemploying the plant cultivation light source. The plant cultivationdevice includes a main body in which a plant is provided, a light sourceprovided in the main body to irradiate a light to the plant, and acontroller controlling the light source. The light source is turned onor turned off depending on a light period and a dark period of theplant. When a portion of the light period is referred to as a firstperiod and the other portion of the light period is referred to as asecond period, the first period and the second period are alternatelyprovided with each other, and lights having different wavelengths fromeach other are provided to the plant in the first and second periods,thereby increasing a content of an active ingredient in the plant.

According to the above, the light source for emitting the light thatincreases the content of the active ingredient while retaining theinherent color of the plant of Asteraceae family plant may be provided.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other advantages of the present disclosure will becomereadily apparent by reference to the following detailed description whenconsidered in conjunction with the accompanying drawings wherein:

FIG. 1A is a cross-sectional view showing a Cichorioideae subfamilyplant cultivation device according to an exemplary embodiment of thepresent disclosure;

FIG. 1B is a view schematically showing a light emitting diode used infirst and second light sources;

FIG. 2 is a cross-sectional view showing a Cichorioideae subfamily plantcultivation device according to an exemplary embodiment of the presentdisclosure;

FIG. 3A is a view showing growth conditions of the Cichorioideaesubfamily plants according to a comparative example and experimentalexamples;

FIG. 3B is a view showing another growth conditions of the Cichorioideaesubfamily plants according to a comparative example and experimentalexamples;

FIG. 4A is a photograph showing an appearance of a green leaf lettuce(Cheongchima) according to a comparative example and an experimentalexample 1;

FIG. 4B is a photograph showing an appearance of a green leaf lettuce(Cheongchima) according to a comparative example and an experimentalexample 2;

FIGS. 5A to 5D are graphs showing a content of an active ingredientcontained in the green leaf lettuce (Cheongchima) after harvest in thecomparative example and experimental example 2 where:

FIG. 5A illustrates that the active ingredient corresponds tochlorogenic acids;

FIG. 5B illustrates that the active ingredient corresponds tochlorophylls;

FIG. 5C illustrates that the active ingredient corresponds toflavonoids; and

FIG. 5D illustrates that the active ingredient corresponds toanthocyanins;

FIGS. 6A to 6C are graphs showing a content of an active ingredientcontained in other Cichorioideae subfamily plants after harvest in thecomparative example and experimental example 2 where:

FIG. 6A illustrates the active ingredient measured with respect tochlorophylls;

FIG. 6B illustrates the active ingredient measured with respect toflavonols; and

FIG. 6C illustrates the active ingredient measured with respect toanthocyanins;

FIGS. 7A to 7F are photographs showing an exterior color of theCichorioideae subfamily plants after harvest in the comparative exampleand experimental example 2 where:

FIG. 7A illustrates a photograph of chicory among the Cichorioideaesubfamily plants;

FIG. 7B illustrates a photograph of red lollo rosso red leaf lettuceamong the Cichorioideae subfamily plants;

FIG. 7C illustrates a photograph of red leaf lettuce (Jeokchukmyeon)among the Cichorioideae subfamily plants;

FIG. 7D illustrates a photograph of red leaf lettuce (Jeokchima) amongthe Cichorioideae subfamily plants;

FIG. 7E illustrates a photograph of romaine lettuce among theCichorioideae subfamily plants; and

FIG. 7F illustrates a photograph of green leaf lettuce (Cheongchima)among the Cichorioideae subfamily plants;

FIGS. 8A and 8B are views showing growth conditions of a red leaflettuce (Jeokchima), where:

FIG. 8A illustrates exemplary growth conditions of the red leaf lettuce(Jeokchima); and

FIG. 8B illustrates another exemplary growth conditions of the red leaflettuce (Jeokchima);

FIGS. 9A to 9D are graphs showing a content of an active ingredient anda weight of the red leaf lettuce (Jeokchima) product after harvest inthe comparative example and experimental examples 1 to 3, where:

FIG. 9A illustrates a graph showing chlorophylls contained in the redleaf lettuce (Jeokchima) after harvest in Comparative example andExperimental examples 1 to 3;

FIG. 9B illustrates a graph showing flavonoids contained in the red leaflettuce (Jeokchima) after harvest in Comparative example andExperimental examples 1 to 3;

FIG. 9C illustrates a graph showing anthocyanins contained in the redleaf lettuce (Jeokchima) after harvest in Comparative example andExperimental examples 1 to 3; and

FIG. 9D illustrates a bio weight at harvest and a dry weight of the redleaf lettuce (Jeokchima).

DETAILED DESCRIPTION OF EMBODIMENTS

The present disclosure may be variously modified and realized in manydifferent forms, and thus specific embodiments will be exemplified inthe drawings and described in detail hereinbelow. However, the presentdisclosure should not be limited to the specific disclosed forms, and beconstrued to include all modifications, equivalents, or replacementsincluded in the spirit and scope of the present disclosure.

Like numerals refer to like elements throughout. In the drawings, thethickness, ratio, and dimension of components are exaggerated foreffective description of the technical content. It will be understoodthat, although the terms first, second, etc. may be used herein todescribe various elements, components, regions, layers and/or sections,these elements, components, regions, layers and/or sections should notbe limited by these terms. These terms are only used to distinguish oneelement, component, region, layer or section from another region, layeror section. Thus, a first element, component, region, layer or sectiondiscussed below could be termed a second element, component, region,layer or section without departing from the teachings of the presentdisclosure. As used herein, the singular forms, “a”, “an” and “the” areintended to include the plural forms as well, unless the context clearlyindicates otherwise.

It will be further understood that the terms “comprises” and/or“comprising”, or “includes” and/or “including”, when used in thisspecification, specify the presence of stated features, integers, steps,operations, elements, and/or components, but do not preclude thepresence or addition of one or more other features, integers, steps,operations, elements, components, and/or groups thereof.

The present disclosure relates to a light source used to cultivateplants and a cultivation device including such a light source.

Plants photosynthesize using a light in a visible light wavelength bandand gain energy through photosynthesis. The photosynthesis of plantsdoes not occur to the same extent in all wavelength bands. The light ina specific wavelength band that plants use for photosynthesis insunlight is called Photosynthetic Active Radiation (PAR), occupies aportion of solar spectrum, and corresponds to a band from about 400nanometers to about 700 nanometers. The light source for plantcultivation according to an exemplary embodiment of the presentdisclosure includes the light in the PAR wavelength band to provide anappropriate light for plant photosynthesis and provides a light in awavelength band to increase the content of ingredients (hereinafter,referred to as “active ingredients”) that positively affect the healthof humans or the plants upon ingestion. In this case, the activeingredients are substances known to be necessary for humans, such aschlorophylls, flavonols, anthocyanins, sesquiterpene lactones, andphenolic compounds.

The light source according to an exemplary embodiment of the presentdisclosure may apply to various types of plants. However, there may bedifferences in the photosynthetic efficiency of the light emitted fromthe light source or the degree of increase in the content of the activeingredients depending on the types of plants. The light source accordingto an exemplary embodiment of the present disclosure may be applied toAsteraceae family plants. In addition, the light source according to anexemplary embodiment of the present disclosure may be applied to aCichorioideae subfamily plant, which belongs to the Asteraceae familyplants. The types of plants according to an exemplary embodiment of thepresent disclosure should not be limited thereto, and the light sourcemay be applied to other types of plants. In the exemplary embodiment ofthe present disclosure, the plants to which the light source is appliedinclude edible Asteraceae family plants, and in particular, theCichorioideae subfamily plant. The Cichorioideae subfamily plant may beat least one of a red leaf lettuce (Jeokchima), a red leaf lettuce(Jeokchukmyeon), a green leaf lettuce (Cheongchima), a red lollo rossored leaf lettuce, a butterhead lettuce, a romaine lettuce, a chicory, adandelion chicory, and a red chicory.

Hereinafter, for the convenience of explanation, the light sourceapplied to the Cichorioideae subfamily plant will be described as arepresentative example.

FIG. 1A is a cross-sectional view showing a plant cultivation device 10according to an exemplary embodiment of the present disclosure.

Referring to FIG. 1A, the plant cultivation device 10 according to thepresent disclosure includes a main body 100 and a light source. Thelight source includes a first light source 200 and a second light source300.

The main body 100 may include an empty space in which seeds 400 of theCichorioideae subfamily are provided and may be provided in a box shapethat is capable of blocking an external light. In the exemplaryembodiment of the present disclosure, the seeds of the Cichorioideaesubfamily may mean seeds of at least one of a red leaf lettuce(Jeokchima), a red leaf lettuce (Jeokchukmyeon), a green leaf lettuce(Cheongchima), a red lollo rosso red leaf lettuce, a butterhead lettuce,a romaine lettuce, a chicory, a dandelion chicory, and a red chicory.

The main body 100 provides an environment in which the seeds 400provided therein may be grown. The main body 100 may have a size suchthat a plurality of seeds 400 may be provided and grown. In addition,the size of the main body 100 may be altered depending on the use of theplant cultivation device 10. For example, in a case where the plantcultivation device 10 is used for a small-scale plant cultivation suchas in-home use, the size of the main body 100 may be relatively small.In a case where the plant cultivation device 10 is used for commercialplant cultivation, the size of the main body 100 may be relativelylarge.

In the exemplary embodiment of the present disclosure, the main body 100may block external light such that the external light is not incidentinto the main body 100. A dark room environment, which is isolated fromthe outside, may be provided inside the main body 100. Therefore, theexternal light may be prevented from being irradiated to the seeds 400arranged in the main body 100. In particular, the main body 100 mayprevent an external visible light from being irradiated to the seeds400. However, the main body 100 may be designed to be partially open toreceive the external light depending on circumstances.

In the exemplary embodiment of the present disclosure, a photocatalystmay be coated on an inner surface of the main body 100. Thephotocatalyst receives the light provided from the first light source200 and activates a photocatalytic reaction. Accordingly, although thedark room environment with a lot of moisture is maintained in the mainbody 100, it is possible to prevent bacteria or fungi from growinginside the main body 100. A photocatalytic material for performing thisfunction may be at least one selected from titanium dioxide (TiO2),zirconia (ZrO2), tungsten oxide (WO3), zinc oxide (ZnO), and tin oxide(SnO2).

The main body 100 may include a culture platform 120 in which theCichorioideae subfamily plant is cultivated.

The seeds 400 of the Cichorioideae subfamily are provided on the cultureplatform 120. The culture platform 120 may support the seeds 400, andsubstantially simultaneously, may provide nutrients to grow the seeds400. Thus, the culture platform 120 may include a culture mediumrequired to grow the seeds 400, and the culture medium may include asoil containing inorganic substances, such as potassium (K), calcium(Ca), magnesium (Mg), sodium (Na), and iron (Fe).

The culture platform 120 may be provided in a structure including theculture medium and a container accommodating the culture medium. Thecontainer may have a box shape in which at least one surface, e.g., anupper surface, is removed. The culture medium and the seeds 400 may beprovided inside the container having the box shape. The seeds 400 may beprovided while being imbedded in the culture medium or placed on asurface of the culture medium depending on its type.

The culture platform 120 may have a size and a shape, which may bemodified depending on the shape of the main body 100 and how toaccommodate the first light source 200 and the second light source 300.The size and the shape of the culture platform 120 may be configured toallow the seeds 400 provided on the culture platform 120 to be placedwithin an irradiation range of the light from the first light source 200and the second light source 300.

A water supply unit 110 is provided in the main body 100 to supply waterto the seeds. The water supply unit 110 may be configured to be disposedat an upper end of the main body 110 and to spray water onto the cultureplatform 120 disposed at a lower end of the main body 110. However, theconfiguration of the water supply unit 110 should not be limited theretoor thereby, and various types of water supply units 110 may be provideddepending on the shape of the main body 100 and the arrangement of theculture platform 120.

The water supply unit 110 may be provided in a singular or pluralnumber. The number of the water supply units 110 may be altereddepending on the size of the main body 110. For instance, in the case ofthe relatively small-sized plant cultivation device 10 for the homeusage, one water supply unit 110 may be used since the size of the mainbody 100 is small. In the case of the relatively large-sized commercialplant cultivation device 10, the plural water supply units 110 may beused since the size of the main body 100 is large. However, the numberof the water supply units should not be limited thereto or thereby, andthe water supply unit may be provided in a variety of positions invarious numbers.

The water supply unit 110 may be connected to a water tank provided inthe main body 100 or a faucet outside the main body 100. In addition,the water supply unit 110 may further include a filtration unit suchthat contaminants floating in the water are not provided to the seeds400. The filtration unit may include a filter, such as an activatedcarbon filter or a non-woven fabric filter, and thus the water passingthrough the filtration unit may be purified. The filtration unit mayfurther include a light irradiation filter. The light irradiation filtermay remove germs, bacteria, fungal spores, and the like, which arepresent in water, by irradiating an ultraviolet light or the like towater. As the water supply unit 110 includes the above-mentionedfiltration unit, the inside of the main body 100 and the seeds 400 maybe less likely contaminated even when water is recycled or rainwater orthe like is directly used for the cultivation.

The water provided from the water supply unit 110 may be provided asplain water itself (for example, purified water) without additionalnutrients, however, it should not be limited thereto or thereby. Thewater provided from the water supply unit 110 may contain nutrientsnecessary for the growth of the plants of the Cichorioideae subfamily.For example, the water may contain a material, such as potassium (K),calcium (Ca), magnesium (Mg), sodium (N), and iron (Fe), and a material,such as nitrate, phosphate, sulfate, and chloride (Cl). For instance,Sachs's solution, Knop's solution, Hoagland's solution, or Hewitt'ssolution may be supplied from the water supply unit 110.

The first light source 200 irradiates the light in a first wavelengthband to the seeds 400. The seeds 400 may grow by being irradiated withthe light in the first wavelength band.

The first wavelength band emitted from the first light source 200 may bea visible light wavelength band. Therefore, the seeds 400 may receivethe light in the first wavelength band, which is emitted from the firstlight source 200, and may perform photosynthesis. The plants may growfrom the seeds 400 by the photosynthesis.

As described above, the first light source 200 may include one or morelight emitting diodes to emit the light in the visible light wavelengthband.

The above-mentioned at least one light emitting diode may be a lightemitting diode that emits a white light or may be a light emitting diodethat emits a color light in various visible lights. For example, whenthe first light source 200 includes plural light emitting diodes, thelight emitting diodes may emit lights having different wavelength bands,respectively. In the exemplary embodiment of the present disclosure, thefirst light source 200 may emit a light in an infrared or near-infraredwavelength band according to circumstances.

In the exemplary embodiment of the present disclosure, when the firstlight source 200 includes plural light emitting diodes, the lightemitting diodes may include, for example, a light emitting diode thatemits a red light, a light emitting diode that emits a blue light, and alight emitting diode that emits a green light, and thus a white lightmay be implemented. Alternatively, the first light source 200 mayinclude the light emitting diode that emits the red light and the lightemitting diode that emits the blue light without including the lightemitting diode that emits the green light.

In the exemplary embodiment of the present disclosure, the plants of theCichorioideae subfamily may receive the red light and the blue lightemitted from the above-mentioned light emitting diodes and may activelyperform photosynthesis. In this case, the red light may promote thephotosynthesis of the plants to accelerate the growth of the plants fromthe seeds 400, and the blue light may contribute to formation of plantleaf from the seeds 400 and may induce flowering of the plants. Thefirst light source 200 may include the light emitting diode that emitsthe green light. The light emitting diode emitting the green light mayincrease a photosynthetic efficiency of the plants.

In the exemplary embodiment of the present disclosure, when the firstlight source 200 includes the light emitting diodes that emit the lightshaving different wavelengths as described above, a composition ratio ofthe light emitting diodes may differ depending on the wavelength. Forexample, the light emitting diodes that emit the red light and the bluelight may be provided less than the light emitting diode that emits thegreen light. A ratio between the light emitting diodes that emit the redlight, the blue light, and the green light may be determined accordingto the type of the seeds 400. For instance, the composition ratio may bealtered depending on a ratio of cryptochrome that is a blue lightreceptor to phytochrome that is a red light receptor. Alternatively, thelight emitting diodes emitting the lights of respective wavelength bandsmay be provided in the same numbers, and in this case, the lightemitting diodes may be driven at different ratios depending on the typeof plant.

Since the light emitting diodes provided in the first light source 200have a waveform having a high peak at a specific wavelength, it ispossible to irradiate the lights customized to the type of the seeds400. Therefore, the plants may grow faster and bigger with less power.In an exemplary embodiment of the present disclosure, the light emittingdiodes of the first light source 200 may include the red light emittingdiode, a white light emitting diode, and the blue light emitting diode.For example, the first light source 200 may include the red lightemitting diode, the white light emitting diode, and the blue lightemitting diode in a ratio of 12:10:32.

The first light source 200 is disposed at a position suitable to providethe light to the seeds 400. For example, the first light source 200 maybe provided on an inner wall of an upper portion or a sidewall portioninside the main body 100. In FIG. 1A, the first light source 200disposed on the upper portion of the main body 100 is shown, and thefirst light source 200 irradiates the light to the seeds 400 provided ona lower portion of the main body 100. The position of the first lightsource 200 may be determined by considering an irradiation angle of thelight from the first light source 200 and a position of the cultureplatform 120 in which the seeds 400 are provided.

In the exemplary embodiment of the present disclosure, the first lightsource 200 may have a waterproof structure. Accordingly, even thoughwater splashes on the first light source 200, the first light source 200may be prevented from having water damage.

The second light source 300 emits light in a second wavelength band tothe seeds 400.

The second wavelength band is different from the first wavelength bandand is the ultraviolet wavelength band in a range from about 250 nm toabout 380 nm. In the exemplary embodiment of the present disclosure, thesecond wavelength band may correspond to at least one wavelength bandamong lights having wavelength bands of a UV-A, a UV-B, and a UV-C. Inthe exemplary embodiment of the present disclosure, the second lightsource 300 may emit a light having a wavelength band from about 280 nmto about 315 nm. As another way, the second light source 300 may emit alight having a wavelength band of about 285 nm. To this end, the secondlight source 300 may include at least one light emitting diode thatemits the light having the above-mentioned wavelength band. Each of thesecond light source 300 or the light emitting diode included in thesecond light source 300 may be provided in a plural number. In thiscase, the light emitting diodes may emit lights having differentwavelengths from each other. For example, the second light source 300may be configured to allow a portion of the second light sources 300 orthe light emitting diodes to emit the light having the wavelength ofabout 285 nm and the other portion of the second light sources 300 orthe light emitting diodes to emit the light having the wavelength ofabout 295 nm.

The second light source 300 is to alter a content of active ingredientsof the seeds 400 and the plants grown from the seeds 400 by irradiatingthe light in the ultraviolet wavelength band to the plants of theCichorioideae subfamily. The content of active ingredients in the seeds400 and the plants of the Cichorioideae subfamily may be altered byirradiating the light emitted from the second light source 300 to theplants of the Cichorioideae subfamily for a predetermined time at apredetermined intensity without affecting the growth of the seeds 400.

The second light source 300 may have a waterproof structure.Accordingly, even though the water splashes on the second light source300, the second light source 300 may be prevented from malfunctioning.

In the exemplary embodiment of the present disclosure, a controller (notshown) for controlling whether to operate or not the first light source200 and the second light source 300 may be connected to the first lightsource 200 and/or the second light source 300 by wire or wirelessly.

The controller may substantially simultaneously or individually controlON/OFF of the first light source 200 and/or the second light source 300such that the first light source 200 and/or the second light source 300emit the lights for a predetermine period at a predetermined intensity.

In the exemplary embodiment of the present disclosure, the controllermay control whether to operate or not the first light source 200 and thesecond light source 300 according to a preset process or according to auser's input. For example, the controller may not operate the first andsecond light sources 200 and 300 for a first time, may operate the firstlight source 200 for a second time, and may operate the second lightsource 300 for a third time in sequence. Alternatively, a user maymanually input a duration of the first time, the second time, and thethird time and an intensity of the light of the first light source 200and/or the second light source 300.

According to the exemplary embodiment of the present disclosure, thecontroller may be connected to the water supply unit in addition to thefirst light source 200 and/or the second light source 300. Thecontroller may control an amount of water supplied through the watersupply unit and a time during which the water is supplied.

For example, the water supply unit 110 may supply water to the seeds 400at predetermined time intervals without a user's operation. Theintervals at which water is supplied to the seeds 400 may be modifieddepending on the type of the seeds 400. In the case of plants of theCichorioideae subfamily that require a lot of water for growth, watermay be supplied at relatively short intervals, and in the case of plantsof the Cichorioideae subfamily that require less water for growth, watermay be supplied at relatively long intervals.

FIG. 1B is a view schematically showing the light emitting diode used inthe first and second light sources.

Referring to FIG. 1B, the light emitting diode may include a lightemitting structure including a first semiconductor layer 223, an activelayer 225, and a second semiconductor layer 227, a first electrode 221connected to the light emitting structure, and a second electrode 229connected to the light emitting structure.

The first semiconductor layer 223 is a semiconductor layer doped with afirst conductive type dopant. The first conductive type dopant may be ap-type dopant. The first conductive type dopant may be Mg, Zn, Ca, Sr,or Ba. In the present exemplary embodiment, the first semiconductorlayer 223 may include a nitride-based semiconductor material. In thepresent exemplary embodiment of the present disclosure, the material forthe first semiconductor layer 223 may be GaN, AlN, AlGaN, InGaN, InN,InAlGaN, or AlInN.

The active layer 225 is disposed on the first semiconductor layer 223and corresponds to a light emitting layer. The active layer 225 is alayer in which electrons (or holes) injected through the firstsemiconductor layer 223 and holes (or electrons) injected through thesecond semiconductor layer 227 meet each other and emit a light due to aband gap difference of an energy band according to a material forforming the active layer 225.

The active layer 225 may be implemented with a compound semiconductor.The active layer 225 may be implemented with, for example, at least oneof compound semiconductors of Groups III-V or II-VI.

The second semiconductor layer 227 is disposed on the active layer 225.The second semiconductor layer 227 is a semiconductor layer doped with asecond conductive type dopant having a polarity opposite to that of thefirst conductive type dopant. The second conductive type dopant may bean n-type dopant, and the second conductive type dopant may be, forexample, Si, Ge, Se, Te, O, or C.

In the exemplary embodiment of the present disclosure, the secondsemiconductor layer 227 may include a nitride-based semiconductormaterial. The material for the second semiconductor layer 227 may beGaN, AlN, AlGaN, InGaN, InN, InAlGaN, or AlInN.

The first electrode 221 and the second electrode 229 may be provided invarious forms to be respectively connected to the first semiconductorlayer 223 and the second semiconductor layer 227. In the presentexemplary embodiment, the first electrode 221 is disposed under thefirst semiconductor layer 223, and the second electrode 229 is disposedon the second semiconductor layer 227; however, they should not belimited thereto or thereby. In the exemplary embodiment of the presentdisclosure, the first electrode 221 and the second electrode 229 mayinclude various metals, such as Al, Ti, Cr, Ni, Au, Ag, Sn, W, Cu, oralloys thereof. Each of the first electrode 221 and the second electrode229 may have a single-layer or multi-layer structure.

In the exemplary embodiment of the present disclosure, the lightemitting diode is described as a vertical type light emitting diode,however, the light emitting diode does not necessarily need to be thevertical type and may be provided in other types as long as itcorresponds to the concept of the present disclosure.

According to the exemplary embodiment of the present disclosure, thefollowing effects may be obtained by using the light emitting diodeinstead of a conventional lamp as a light source for applying the lightto a sample.

When the light emitting diode according to the exemplary embodiment ofthe present disclosure is used as the light source, a light having aspecific wavelength may be provided to the plants when compared with alight emitted from the conventional lamp (e.g., a conventional UV lamp).The light emitted from the conventional lamp has a broad spectrum in awide area compared with that of the light emitted from the lightemitting diode. Accordingly, in the case of the conventional UV lamp, itis not easy to separate only the light of some bands from the wavelengthband of the emitted light. In contrast, the light emitted from the lightemitting diode has a sharp peak at a specific wavelength and provides alight of a specific wavelength having a very narrowfull-width-half-maximum in comparison with the light from theconventional lamp. Therefore, it is easy to select the light of thespecific wavelength, and only the light of the selected specificwavelength may be provided to the sample.

In addition, in the case of the conventional lamp, it is difficult toprecisely limit an amount of the light while providing the light to thesample, but in the case of the light emitting diode, it is possible toclearly limit the amount of the light while providing the light.Further, in the case of the conventional lamp, it is difficult toprecisely limit the amount of the light, and thus, an irradiation timemay be set in a wide range. However, in the case of the light emittingdiode, the light required for the sample may be provided for a definitetime within a relatively short time.

As described above, in the case of the conventional lamp, it isdifficult to clearly determine the amount of the light due to therelatively wide wavelength, the wide range of light amount, and the widerange of irradiation time. In contrast, in the case of the lightemitting diode, a clear light dose may be provided due to the relativelynarrow range of wavelength, the narrow range of light amount, and thenarrow range of irradiation time.

In addition, in the case of the conventional lamp, it takes a long timeto reach a maximum amount of light after turning on the power. Incontrast, when using the light emitting diode, it reaches the maximumamount of light with substantially no warm-up time after turning on thepower. Thus, in the case of the light emitting diode light source, theirradiation time of the light may be accurately controlled when theplants are irradiated with a light of a specific wavelength.

In the exemplary embodiment of the present disclosure, the content ofthe active ingredients may be altered by irradiating the light to theAsteraceae family plants, for example, the Cichorioideae subfamilyplant, by using the first and second light sources under a specificcondition.

As the active ingredients whose content is altered in plants by thelight from the first and second light sources, there may bechlorophylls, flavonols, anthocyanins, sesquiterpene lactones, andphenolic compounds.

Chlorophylls are known as a photosynthetic pigment of green vegetablesand help to prevent bad breath and constipation. Flavonols areantioxidants and include quercetin, kaempferol, and myricetin as itsrepresentative substances. Quercetin is an antioxidant with highantioxidant capacity, Kaempferol is known to prevent cancer cellproliferation by enhancing immunity, and Myricetin is known to inhibitaccumulation of fat to prevent cardiovascular disease. Anthocyanins areone of representative antioxidants and have the effect of preventingaging by removing reactive oxygen species in human body. Anthocyaninsalso help re-synthesis of a pigment called rhodopsin in the eye's retinato prevent eye strain, decreased visual acuity, cataract, etc.

Sesquiterpene-based compounds (sesquiterpenoids) are a subgroup ofterpene-based compounds (terpenoids), and among them, the sesquiterpenelactones having a lactone structure are known to have functions, such asantitumor activity, cytotoxicity alleviation, and antibacterial action.In particular, lactucin, which belongs to the group of sesquiterpenelactones contained in lettuce, has an effect in improving insomnia. Inaddition, it is known that the sesquiterpene lactones have relativelygood medicinal value in terms of resistance to microbial pathogens,treatment of schistosome infection, and improvement of antiallergicactivity.

According to the exemplary embodiment, in a case where an ultravioletlight is applied in a predetermined condition during the cultivation ofthe seeds of the Cichorioideae subfamily, the sesquiterpene lactones mayincrease or decrease. When the sesquiterpene lactones increase inplants, it may help to improve insomnia. When the sesquiterpene lactonesdecrease in the plants, the sleep-inducing phenomenon may be preventedeven when the plants of the Cichorioideae subfamily are ingested.

The sesquiterpene lactones may be a substance represented by thefollowing chemical formula 1, and each of R1 and R2 may independently bevarious functional groups. Each of R1 and R2 may independently be, forexample, substituted or unsubstituted alkyl, alkoxy, allyl, or aryl withfrom 1 to 18 carbon atoms.

In the exemplary embodiment of the present disclosure, the sesquiterpenelactones may be at least one of lactucin, lactucopicrin,8-deoxylactucin, picriside A, crepidiaside A, lactucin-15-oxalate,lactucopicrin-15-oxalate, 8-deoxylactucin-15-oxalate,15-deoxylactucin-8-sulfate, 15-deoxylactucin,8-deoxylactucin-15-sulfate, and15-(4-hydroxyphenylacetyl)-lactucin-8-sulfate.

As another example, the sesquiterpene lactones according to theexemplary embodiment of the present disclosure may have the followingformulas 2-1 to 2-7.

In the exemplary embodiment of the present disclosure, the lightirradiated from the second light source 300 increases the phenoliccompound in the plants grown from the seeds 400. In detail, the lightirradiated from the second light source 300 and having the secondwavelength band activates secondary metabolism of the plants, and thusthe content of the phenolic compounds, which are secondary metabolites,may increase. When the light in the second wavelength band is irradiatedto the plants, the light having the above-described wavelength causes aDNA-damaging effect on cells of the plants, and as a result, thegeneration of phenolic compounds, which are capable of absorbing thelight having the above-mentioned wavelength, may be promoted. Thephenolic compounds correspond to antioxidants included in the plantsgrown from the seeds 400.

In the exemplary embodiment of the present disclosure, the phenoliccompounds may include substances represented by the following chemicalformulas 3-1 to 3-3. The substances represented by the followingformulas 3-1 to 3-3 correspond respectively to luteolin, chlorogenicacid, and chicoric acid. In this case, chlorogenic acid is a naturalcompound composed of an ester of caffeic acid and quinic acid and is abiological antioxidant. The chlorogenic acid is known to neutralizedamaging effects of peroxides.

According to the exemplary embodiment of the present disclosure, whenthe light is irradiated to the Asteraceae family plant, for example, theCichorioideae subfamily plant, by using the first and second lightsources under a specific condition, the content of the activeingredients may increase, and also, the effect of having and retainingthe inherent color of each Cichorioideae subfamily plant may beobtained.

According to an exemplary embodiment of the present disclosure, when thelight source for plant cultivation is used, it is possible toindependently provide a growing environment suitable for the types ofplants even under conditions in which the sunlight is insufficient, orthe sunlight is not provided. Particularly, the marketability of plantsmay increase by providing the growth environment that may retain theinherent color of the plants. In the case of a conventional plantfactory that grows plants without sunlight, the plants grown in theplant factory have no anthocyanin or very small amounts of anthocyanins,and as a result, the plants have a problem in that they do not have theinherent color of the plants. For example, the Chicoriaceae subfamilyplant such as the red leaf lettuce (Jeokchima) usually appear reddish,but appear very pale reddish or have no red color when they are grown inthe plant factory without sunlight. In a case where the plant does nothave the inherent color it should have, a consumer may determine thatthe plant is defective, resulting in poor marketability. However,according to the exemplary embodiment of the present disclosure, thecontent of anthocyanin among the active ingredients of the plantsignificantly increases by appropriately applying the first light andthe second light to the plant, particularly, by applying the secondlight to the plant for a predetermined time duration before harvesting,and as a result, the plant has a color close to its inherent color. Thisleads to an improvement in the marketability. In the exemplaryembodiment of the present disclosure, the light provided to theAsteraceae family plants, for example, the Cichorioideae subfamily plantmay be provided during different periods. Here, the term “period” meansa temporal period. For example, when the light emitted from the firstlight source is referred to as a “first light” and the light emittedfrom the second light source is referred to as a “second light”, thelight corresponding to the first light may be provided during a portionof the period, and both the first light and the second light may beprovided during the other portion of the period except for the portionof the period. Hereinafter, for convenience of explanation, the periodin which the first light is provided will be referred to as a “firstperiod”, and the period in which the first light and the second lightare provided will be referred to as a “second period”. In other words,only the above-described first light source may be turned on in thefirst period, and both the first light source and the second lightsource may be turned on in the second period.

In the present exemplary embodiment of the present disclosure, the firstperiod, or the second period is a period in which the light having thevisible light wavelength band is provided and corresponds to apredetermined period in the light condition. In the present exemplaryembodiment of the present disclosure, the second period is shorter thanthe first period.

In the present exemplary embodiment of the present disclosure, the firstperiod and the second period may be arranged in various ways dependingon the growth stage and the harvest time of the plants. For example, thefirst period may be arranged before the harvesting of the plants afterthe plants are transplanted. The second period may be arranged adjacentto the first period and may be arranged right before the harvesting timewithin an overall schedule. In other words, the first period may becontinued after the transplanting of the plants, and the second periodmay be arranged at a time other than the first period right beforeharvesting. Then, the plants are harvested. In the exemplary embodimentof the present disclosure, the second period may be provided between thefirst periods over 10 days or less before harvesting. In someembodiments, the second period may be provided between the first periodsover several days. In this case, a cumulative applied amount of theprovided second light may be, for example, about 4.032 kJ/m², about2.880 kJ/m², or about 2.304 kJ/m².

In the present exemplary embodiment of the present disclosure, theplants may be cultivated under the light period and the dark period,which are alternated for about 20 days after the transplanting of theplants. That is, the first period and the second period are sequentiallyrepeated in the light period, and the first period and the secondperiod, which are next to each other, form a one repetition period. Inthe repetition period, the light provided in the second period is notprovided in the first period.

After being transplanted, the light period may include only the firstperiod for about 14 days (e.g., from tenth day to twenty-third day aftersowing). Then, the light period may include the first period and thesecond period, which are alternately arranged with each other, for about7 days from fifteenth day to twentieth day after being transplanted(e.g., from twenty-fourth day to thirtieth day after sowing). That is,the first period and the second period are sequentially repeated in thelight period. In other words, the irradiation of light is repeated witha cycle of about 10 minutes, and the second light is irradiated forabout 1 minute and then has a rest period of about 9 minutes. This cycleis continuously repeated during the light period.

In the present exemplary embodiment of the present disclosure, acumulative energy amount per day of the second light irradiated to theplant during the second period may be about 0.58 kJ/m², and a totalcumulative energy amount from the sowing to the harvest may be about4.03 kJ/m². In the above descriptions, the simple Cichorioideaesubfamily plant cultivation device in a simple form according to theexemplary embodiment of the present disclosure has been described.However, since the Cichorioideae subfamily plant cultivation deviceaccording to the exemplary embodiment of the present disclosure may beused for commercial plant production, other forms of the Cichorioideaesubfamily plant cultivation device for use in commercial plantproduction will be described in detail.

FIG. 2 is a cross-sectional view showing the Cichorioideae subfamilyplant cultivation device according to an exemplary embodiment of thepresent disclosure.

The plant cultivation device 10 according to an exemplary embodiment ofthe present disclosure may be operated in the form of a large factoryfor obtaining a large amount of plants of the Cichorioideae subfamily,i.e., a plant production facility, as well as a culturing device forhome use or personal use to cultivate a relatively small amount ofplants of the Cichorioideae subfamily. Therefore, the plant cultivationdevice 10 may include a plurality of culture platforms 120, first lightsources 200, second light sources 300, and water supply units (notshown).

As shown in figures, the culture platforms 120, the first light sources200, and the second light sources 300 may define several compartments.Therefore, a main body 100 may be provided in a structure that includesthe several compartments.

The several compartments included in the main body 100 may be operatedindependently of each other. For example, the first light source 200provided in some compartments may emit more blue light than red light,and the first light source 200 provided in other compartments may emitmore red light than blue light. In addition, each compartment of themain body 100 may be operated differently in terms of time. For example,the first light source 200 may emit the light in a first wavelength bandin some compartments to grow plants 401, and the second light source 200may emit the light in a second wavelength band in other compartments toincrease or decrease the active ingredient content in the plants 401.

Each compartment included in the main body 100 may be configured to forma closed dark room to be independently operated as described above.Therefore, the light(s) emitted from the first light source 200 and/orthe second light source 300 and provided to an arbitrary compartment maynot exert an influence on other compartments.

The culture platform 120 provided in the main body 100 may includedifferent culture media from each other depending on the type of theplants 401. Thus, it is possible to provide the growth environmentcustomized to the type of the plants 401. In addition, the cultureplatform 120 may be separated from the main body 100. Accordingly, whenthe plants 401 growing on some culture platforms 120 reach a harvestingstage, users may separate only the culture platform 120 on which theplants 401 completely grown are provided from the main body 100 withoutaffecting the plant cultivation device 10.

The main body 100 may further include a water supply unit, and the watersupply unit is provided on a surface at which the main body 100 and theculture platform 120 contact each other to directly supply water to theculture medium included in the culture platform 120. Therefore,different from a spray-type water supply unit, water may be suppliedwithout affecting other culture platforms 120 even when the cultureplatforms 120 are stacked.

Two or more of the first light source 200 may be provided depending onshape of the culture platform 120. As described above, the first lightsource 200 may include a plurality of light emitting diodes that emitslights having different wavelengths, and the light emitting diodes maybe provided in the same ratio or different ratios in the first lightsource 200. When the light emitting diodes that emit the lights havingthe different wavelengths are provided in the same ratio in the firstlight source 200, the first wavelength band may be controlled by acontroller to correspond to the type of the plants 401. Therefore, thegrowth environment suitable for the type of the plants 401 may beprovided.

Two or more of the second light source 300 may be provided. The secondlight sources 300 may be provided in different compartments from eachother in the main body 100 and may be independently operated.Accordingly, the light in the second wavelength band may be irradiatedto only the completely grown plants 401 in a phase where the activeingredient content is to be increased or decreased.

In the exemplary embodiment of the present disclosure, various sensors,e.g., a temperature sensor, a humidity sensor, and a light intensitysensor, may be additionally disposed in the controller of the plantcultivation device operated in the plant production facility, and thecontroller may receive data from the sensors and may control the firstand second light sources and the water supply unit as a whole orindividually. The culturing device equipped with the plant cultivationsystem may transmit and receive data either directly or from a remotelocation by wired, wireless, or internet connection and may display datafrom the various sensors, the first and second light sources, and thewater supply unit through a separate display. The user may instruct thecontroller 40 to implement optimal conditions after reviewing such data.

As described above, the plants of the Cichorioideae subfamily with thealtered active ingredient content may be easily cultivated in largequantities by using the plant cultivation device 10 according to theexemplary embodiment of the present disclosure. Through the culturingmethod as the exemplary embodiment of the present disclosure, it ispossible to obtain a large amount of non-synthetic active ingredients ina natural state. The active ingredients obtained in large quantity maybe processed in the form of medicines, health supplements, and variousingredients through a separate processing process. For example, theplants of the Cichorioideae subfamily with a high active ingredientcontent may be lyophilized immediately after harvest to allow thehighest active ingredient content right after harvest to be maintainedin the final product. The lyophilized plants of the Cichorioideaesubfamily may be processed into various forms. For example, they may beprocessed in powder form or may be processed to extract only the activeingredients through a separate process. Thus, users may consume plantsof the Cichorioideae subfamily having the high active ingredient contenteither in the form of plants or in the form of processed productsthrough separate processing processes.

Further, the plural plants 401 may be substantially simultaneouslycultivated using the plant cultivation device according to the exemplaryembodiment of the present disclosure, and the growth environmentsuitable for the type of the plants 401 may be independently provided.Accordingly, the plants 401 whose types are different from each othermay be substantially simultaneously cultivated by using the plantcultivation device 10.

According to the exemplary embodiment of the present disclosure, whenthe light source for plant cultivation is used, it is possible toindependently provide a growing environment suitable for the types ofplants even under conditions in which the sunlight is insufficient, orthe sunlight is not provided. In addition, the plant that has theinherent color thereof and having the high active ingredient content maybe easily cultivated.

Embodiment

1. Growth Conditions and Light Treatment Conditions for Plants 1

In the following embodiment examples, experiments were carried out onthe Cichorioideae subfamily plant, which belongs to the Asteraceaefamily plants, as a representative example. The Cichorioideae subfamilyplant was harvested on the 31st day (grown for 31 days). TheCichorioideae subfamily plant was cultivated under conditions of atemperature of about 22±1° C. and a relative humidity of about 70±10%during the growth period. The first and second lights were provided bythe light emitting diode during the growth period.

The growth conditions of a comparative example and experimental exampleswere shown in FIGS. 3A and 3B. Hereinafter, for the convenience ofexplanation, the period in which the first light is provided isrepresented as the first period, and the period in which the first andsecond lights are provided is represented as the second period.

Referring to FIGS. 3A and 3B, the Cichorioideae subfamily plant wasgerminated in the dark period for about 2 days after the sowing. Inother words, seeds of the Cichorioideae subfamily plant were first sowedinto a cultivation sponge and germinated in the dark period for about 2days to grow the Cichorioideae subfamily plant.

The Cichorioideae subfamily plant was grown in the light period and thedark period from day 3 to day 9 after sowing, and this corresponds to anirradiation period before transplanting. The light was irradiated to theCichorioideae subfamily plant in the light period at a light intensityof about 60 μmol/m2/s PPFD (Photosynthetic Photon Flux Density). Onlythe purified water was provided to the plants after sowing and beforetransplanting.

The grown sprouts were transplanted in a deep-flow technique (DFT)hydroponic culture system on the 10th day. The transplantedCichorioideae subfamily plant was grown in nutrient solution under thelight and dark periods. As the nutrient solution, Hoagland stocksolution was used, and the pH of the nutrient solution was maintained atabout 5.5 to about 6.5.

In the comparative example, after the transplanting, the light periodand the dark period were provided on the 24-hour basis for about 20days. On the 24-hour basis, the light period was maintained for about 16hours, and the dark period was maintained for about 8 hours. After thetransplanting, the first light was provided in the light period forabout 20 days, and the second light was not provided. That is, in thecase of comparative example, the irradiation period after thetransplanting may include only the first period in the light period. Inthis case, the first light was irradiated in the light period at a lightintensity of about 150 μmol/m2/s PPFD (Photosynthetic Photon FluxDensity).

In experimental example 1, after the transplanting, the light period andthe dark period were provided on the 24-hour basis for about 20 days. Onthe 24-hour basis, the light period was maintained for about 16 hours,and the dark period was maintained for about 8 hours. After thetransplanting, the first light was provided in the light period forabout 20 days, and the second light was provided for about 6 hours atthe start of the light period on 20th day after the transplanting.Accordingly, in experimental example 1, the irradiation period after thetransplanting may include only the first period in the light period forabout 19 days and may include the second period and the first period inthe light period on 20th day. In detail, in experimental example 1, thefirst light was continuously irradiated during the light period on 20thday (on 30th day after sowing) after transplanting, and the second lightwas continuously irradiated for about 6 hours in some periods. Here, thefirst light was irradiated in the light period at a light intensity ofabout 150 μmol/m2/s PPFD (Photosynthetic Photon Flux Density), and atotal cumulative energy amount of the second light provided in thesecond period was about 2.16 kJ/m².

In experimental example 2, after the transplanting, the light period andthe dark period were provided on the 24-hour basis for about 20 days. Onthe 24-hour basis, the light period was maintained for about 16 hours,and the dark period was maintained for about 8 hours. In experimentalexample 2, the second light was irradiated to the plants in an on andoff manner in the light period. That is, the irradiation of the secondlight was repeated with a 10-minutes cycle in which a 1-minuteirradiation of the second light is followed by a 9-minutenon-irradiation in the light period. In experimental example 2, anamount of UV irradiation energy processed per day was about 0.576 kJ/m².In experimental example 2, the UV was irradiated after sowing, and atotal amount of UV irradiation energy was about 4.032 kJ/m².

In the comparative Example, experimental example 1, and experimentalexample 2, only the irradiation of the second light, the irradiationtime of the second light, and the irradiation energy of the second lightwere different, and all other conditions were kept the same. In thiscase, the first light was a light having the visible light wavelengthband, and the second light was a light having a UVB wavelength band, forexample, a wavelength of about 285 nm.

Then, the Cichorioideae subfamily plant was harvested on thirty-firstday.

2. Comparison of Appearance of Green Leaf Lettuce (Cheongchima)According to Comparative Example and Experimental Examples 1 and 2

In this experiment, green leaf lettuce (Cheongchima) was cultivated asComparative example and Experimental examples 1 and 2 under theconditions shown in FIGS. 3A and 3B, and was examined for damage to itsappearance after harvesting.

FIG. 4A is a photograph showing the appearance of the green leaf lettuce(Cheongchima) according to the comparative example and experimentalexample 1. FIG. 4B is a photograph showing the appearance of the greenleaf lettuce (Cheongchima) according to Comparative example andExperimental example 2. In FIG. 4A, the left green leaf lettuce(Cheongchima) corresponds to Comparative example, and the right greenleaf lettuce (Cheongchima) corresponds to Experimental example 1. InFIG. 4B, the left green leaf lettuce (Cheongchima) corresponds to theComparative example, and the right green leaf lettuce (Cheongchima)corresponds to Experimental example 2.

Referring to FIGS. 4A and 4B, there was no damage to appearance in theComparative example. However, leaf curling phenomenon in which leavesare dried and curled at the tip was observed and leaves turned brown inExperimental example 1. On the other hand, in Experimental example 2, nodifference was found from Comparative example, and there was no damageto the overall appearance.

As described above, in Experimental example 1, although the cumulativeenergy amount of the second light was about 2.16 kJ/m², which is muchsmaller than the cumulative energy amount the second light of about 4.03kJ/m² in Experimental example 2, it was found that the damage of theappearance was very large. It is determined that the damage ofappearance was due to the continuous irradiation of the second light.Accordingly, it was found that the damage of appearance was minimized inthe case of light irradiation in an on and off manner even though theamount of energy was large.

3. Comparison of Active Ingredient Content of Comparative Example andExperimental Example 2

FIGS. 5A to 5D are graphs showing the content of the active ingredientscontained in the green leaf lettuce (Cheongchima) after harvest inComparative example and Experimental example 2. The active ingredientsin FIGS. 5A to 5D sequentially correspond to chlorogenic acids,chlorophylls, flavonoids, and anthocyanins.

To obtain results according to Comparative example and Experimentalexample 2, the plants were harvested on the 31st day after sowing, andcontents of chlorogenic acids, chlorophylls, flavonols, and anthocyaninswere measured by providing a light to the leaf using an optical sensorcalled Dualex, that is a non-destructive analyzer. A total of 18 greenleaf lettuces (Cheongchima) were measured (n=18).

Referring to FIGS. 5A to 5D, in Experimental example 2, a significantincrease in the content of active ingredients was observed in comparisonwith the Comparative example. That is, when the second light is appliedto the plants, the active ingredients corresponding to chlorogenicacids, chlorophylls, flavonols, and/or anthocyanins were significantlyincreased.

4. Comparison of Other Cichorioideae Subfamily Plants of ComparativeExample and Experimental Example 2

FIGS. 6A to 6C are graphs showing the content of the active ingredientscontained in other Cichorioideae subfamily plants after harvest inComparative example and Experimental example 2.

In FIGS. 6A and 6B, chicory, red lollo rosso red leaf lettuce, red leaflettuce (Jeokchukmyeon), red leaf lettuce (Jeokchima), and green romainewere experimented as the Cichorioideae subfamily plant, and in FIG. 6C,chicory, red lollo rosso red leaf lettuce, red leaf lettuce(Jeokchukmyeon), and green romaine were experimented as theCichorioideae subfamily plant. Each active ingredient was measured withrespect to chlorophylls, flavonols, and anthocyanins, and the graphs ofFIGS. 6A, 6B, and 6C sequentially correspond to chlorophylls, flavonols,and anthocyanins.

To obtain results according to Comparative example and Experimentalexample 2, each of the plants were harvested on the 31^(st) day aftersowing, contents of chlorophylls, flavonols, and anthocyanins weremeasured by providing a light to the leaf using an optical sensor calledDualex, is a non-destructive analyzer. A total of 18 plants weremeasured (n=18).

Referring to FIGS. 6A to 6C, it was found that the active ingredients inchicory, red lollo rosso red leaf lettuce, red leaf lettuce(Jeokchukmyeon), red leaf lettuce (Jeokchima), and green romainecorresponding to the Cichorioideae subfamily plant were significantlyincreased in experimental example 2 compared with the comparativeexample.

5. Comparison of Exterior Color of Cichorioideae Subfamily Plants ofComparative Example and Experimental Example 2

FIGS. 7A to 7F are photographs showing the exterior colors of theCichorioideae subfamily plants after harvest in Comparative example andExperimental example 2.

FIGS. 7A to 7F are photographs of chicory, red lollo rosso red leaflettuce, red leaf lettuce (Jeokchukmyeon), red leaf lettuce (Jeokchima),romaine lettuce, and green leaf lettuce (Cheongchima) among theCichorioideae subfamily plants in sequence. In FIGS. 7A to 7F, the leftplant corresponds to the result in Comparative example of eachCichorioideae subfamily plant, and the right plant corresponds to theresult in Experimental example 2 of each Cichorioideae subfamily plant.

Referring to FIGS. 7A to 7F, no damage to appearance was observed in allof Comparative example and Experimental example 2. However, Comparativeexamples were all green. On the other hand, in Experimental example 2,in the case of the plant in which the inherent color is partially red,for example, red llolo lettuce, red leaf lettuce (Jeokchukmyeon), andred leaf lettuce (Jeokchima), it is clear that the results according toExperimental example 2 were significantly red compared with the resultaccording to Comparative examples. The red color of the plants is due toanthocyanins, and thus it may be concluded from the above experimentalresult that the content of anthocyanins was increased by applying thesecond light to the plants, thereby affecting the color of the plants.

6. Growth Conditions and Light Treatment Conditions for Plants 2

In the following embodiment examples, experiments were carried out onthe red leaf lettuce (Jeokchima) among the Cichorioideae subfamilyplants, which belong to the Asteraceae family plants, as arepresentative example. The Cichorioideae subfamily plant was cultivatedunder conditions of a temperature of about 22±1° C. and a relativehumidity of about 70±10% during the growth period. The first and secondlights were provided using light emitting diodes during the growthperiod.

The red leaf lettuce (Jeokchima) was harvested on the 31st day (grownfor 31 days). The growth conditions of the red leaf lettuce (Jeokchima)according to Comparative example and Experimental examples are shown inFIGS. 8A and 8B. Hereinafter, in drawings, for the convenience ofexplanation, a period during which the first light is irradiated isshown as the first period, and a period during which the first andsecond lights are irradiated is shown as the second period.

Referring to FIGS. 8A and 8B, the red leaf lettuce (Jeokchima) wasgerminated in the dark period for about 2 days after sowing. In otherwords, red leaf lettuce (Jeokchima) seeds were first sowed into acultivation sponge and germinated in the dark period for about 2 days togrow the red leaf lettuce (Jeokchima).

The red leaf lettuce (Jeokchima) was grown in the light period and thedark period from day 3 to day 9 after sowing, and this corresponds to anirradiation period before transplanting. The first light was irradiatedto the red leaf lettuce (Jeokchima) in the light period at a lightintensity of about 60 μmol/m2/s PPFD. Only the purified water wasprovided to the plants after sowing and before transplanting.

The grown sprouts were transplanted in a deep-flow technique (DFT)hydroponic culture system on the 10th day. The transplanted red leaflettuce (Jeokchima) was grown with nutrient solution under the light anddark periods. As the nutrient solution, Hoagland stock solution wasused, and the pH of the nutrient solution was maintained at about 5.5 toabout 6.5.

In Comparative example, after the transplanting, the light period andthe dark period were provided on the 24-hour basis for about 20 days. Onthe 24-hour basis, the light period was maintained for about 16 hours,and the dark period was maintained for about 8 hours. After thetransplanting, the first light was provided in the light period forabout 20 days, and the second light was not provided. That is, in thecase of Comparative example, the irradiation period after thetransplanting may include only the first period in the light period. Inthis case, the first light was irradiated in the light period at a lightintensity of about 150 μmol/m2/s PPFD.

In Experimental examples 1 to 3, after the transplanting, the lightperiod and the dark period were provided on the 24-hour basis for about20 days. On the 24-hour basis, the light period was maintained for about16 hours, and the dark period was maintained for about 8 hours. InExperimental examples 1 to 3, the second light was irradiated to theplants in the on and off manner in the light period. That is, inExperimental examples 1 to 3, the second light was irradiated in an onand off manner with a repeated cycle of about several minutes in whichlight irradiation of several minutes is followed by a rest period of apredetermined time. In experimental examples 1 to 3, an amount of UVirradiation energy processed per a day was about 0.576 kJ/m², the methodof irradiation was the same with each other, and only the date fromwhich the treatment started and the total amount of irradiation energywere different in each experimental examples.

In Experimental example 1, the UV was irradiated after sowing, and atotal amount of UV irradiation energy was about 2.304 kJ/m². InExperimental example 2, the UV was irradiated after sowing, and a totalamount of UV irradiation energy was about 2.880 kJ/m². In Experimentalexample 3, the UV was irradiated after sowing, and a total amount of UVirradiation energy was about 4.302 kJ/m².

7. Comparison of Active Ingredient Content of Comparative Example andExperimental Examples 1 to 3

FIGS. 9A to 9D are graphs showing the content of the active ingredientscontained in the red leaf lettuce (Jeokchima) after harvest inComparative example and Experimental examples 1 to 3. FIGS. 9A to 9Dshow the content of the active ingredients, and the active ingredientsin FIGS. 9A to 9C sequentially correspond to chlorophylls, flavonoids,and anthocyanins. FIG. 9D shows a bio weight at harvest and a dry weightof the red leaf lettuce (Jeokchima).

To obtain results according to Comparative example and Experimentalexamples 1 to 3, the plants were harvested on the 31^(st) day aftersowing, and contents of chlorophylls, flavonols, and anthocyanins weremeasured by providing a light to the leaf using an optical sensor calledDualex, that is a non-destructive analyzer. A total of 18 red leaflettuces (Jeokchima) were measured (n=18). Then, nine plants wereharvested to measure the bio weight (n=9), and five plants among thenine plants were lyophilized for about 3 days after suspension ofbioactivity with liquid nitrogen to measure the dry weight (n=5).

FIG. 9A is a graph of the chlorophyll content, and all experimentalexamples 1, 2, and 3 showed higher values than Comparative example.Experimental examples 1 and 3 showed similar values, Experimentalexample 2 was higher than Comparative example and lower thanExperimental example 3, but there was no significant difference fromExperimental example 1. The chlorophyll content in Experimental examples1, 2 and 3 was increased by about 28.1%, about 18.4%, and about 38.6%,respectively, compared to Comparative examples.

FIG. 9B is a graph of the flavonol content, and all Experimentalexamples 1, 2, and 3 showed higher values than Comparative example.There was no substantial difference between experimental examples 1 to3. The flavonol content in Experimental examples 1, 2 and 3 increased byabout 203.7%, about 188.9%, and about 213.8%, respectively, compared tothe comparative examples.

FIG. 9C is a graph of the anthocyanin content, and all Experimentalexamples 1, 2, and 3 showed higher values than the comparative example.There was no substantial difference between Experimental examples 1 to3. The anthocyanin content in experimental examples 1, 2 and 3 increasedby about 66.9%, about 71.2%, and about 74.5%, respectively, compared tothe comparative examples.

FIG. 9D is a graph of the bio weight and the dry weight, and there wasno substantial difference in the bio weight and the dry weight betweenComparative example and Experimental example 1. There was no differencein the bio weight between Comparative example and Experimental example2, however, the dry weight was reduced by about 16.9%. Experimentalexample 3 showed lower bio weight and dry weight than Comparativeexample, the bio weight was reduced by about 21.0%, and dry weight wasreduced by about 23.1%.

Consequently, it was found that the total cumulative energy amountshould not exceed about 2.304 kJ/m², as in Experimental example 1, tomeet the conditions under which functional materials may increasewithout affecting the bio weight and the dry weight.

Although the exemplary embodiments of the present disclosure have beendescribed, it is understood that the present disclosure should not belimited to these exemplary embodiments but various changes andmodifications can be made by one ordinary skilled in the art within thespirit and scope of the present disclosure as hereinafter claimed.

Therefore, the disclosed subject matter should not be limited to anysingle embodiment described herein, and the scope of the presentinventive concept shall be determined according to the attached claims.

We claim:
 1. A plant cultivation light module comprising: a first lightsource comprising a first light emitter configured to emit first lighthaving peak wavelength in a visible range and a second light emitterconfigured to emit second light having a longer peak wavelength to thefirst light; a second light source comprising a plurality of third lightemitters configured to emit third light having a shorter peak wavelengthto the first light; and a controller configured to control the firstlight emitter, the second light emitter and a plurality of the thirdlight emitters such that a first light pattern and a second lightpattern are generated; wherein the first light source and the secondlight source further comprise: a first semiconductor layer, a secondsemiconductor layer, and an active layer, the active layer beingdisposed on the first semiconductor layer to emit a light having aspecific wavelength due to a band gap difference in an energy banddepending on a material used to form the active layer, wherein the firstlight pattern provides a first light spectrum and the second lightpattern provides a second light spectrum having at least one more peakwavelength than the first light spectrum, and wherein the first lightsource supplies, to the plant, light of the first light pattern and thesecond light source supplies, to the plant, light of the second pattern.2. The plant cultivation light module of claim 1, wherein the firstlight source comprises a plurality of first light emitters and aplurality of second light emitters, and a composition ratio of theplurality of first light emitters and the plurality of second lightemitters differ.
 3. The plant cultivation light module of claim 1,wherein the second light emitter is further configured to emit light inan infrared wavelength band or near-infrared wavelength band.
 4. Theplant cultivation light module of claim 1, wherein the plurality ofthird light emitters is further configured to emit light of anultraviolet wavelength band.
 5. The plant cultivation light module ofclaim 4, wherein the plurality of third light emitters is furtherconfigured to emit the third light having a sharp peak at a specificwavelength having a narrower FWHM than a UV lamp thereof.
 6. The plantcultivation light module of claim 1, wherein the controller controls thefirst light source and the second light source individually.
 7. Theplant cultivation light module of claim 1, wherein the controllercontrols operations of the first light source and second light sourcewirelessly.
 8. The plant cultivation light module of claim 1, whereinthe plurality of third light emitters is configured to provide, to theplant, the third light correlated to increase a content of an activeingredient in the plant, wherein the active ingredient comprises atleast one of chlorophylls, flavonoids, anthocyanins, chlorogenic acids,sesquiterpene lactones, and phenolic compounds.
 9. The plant cultivationlight module of claim 1, wherein: the first light source comprises aplurality of first light emitters and a plurality of second lightemitters; and a composition ratio of the plurality of first lightemitters and the plurality of second light emitters is identical and theplurality of first light emitters and the plurality of second lightemitters are driven at different ratios depending on a type of theplant.
 10. A plant cultivation device, comprising: a main body housing aplant; a light source provided in the main body to irradiate a light tothe plant; and a controller controlling the light source; wherein thelight source comprises: a first light source comprising a first lightemitter configured to emit first light having peak wavelength in avisible range and a second light emitter configured to emit second lighthaving a longer peak wavelength to the first light emitter, a secondlight source comprising a plurality of third light emitters configuredto emit third light having a shorter peak wavelength to the first lightemitter, and wherein the controller is configured to control the firstlight emitter, the second light emitter, and the plurality of thirdlight emitters such that a first light pattern and a second lightpattern are provided, the first light source and the second light sourcefurther comprising a first semiconductor layer, a second semiconductorlayer, and an active layer, the active layer being disposed on the firstsemiconductor layer to emit a light having a specific wavelength due toa band gap difference in an energy band depending on a material used toform the active layer; wherein the first light pattern provides a firstspectrum and the second light pattern provides a second spectrum havingat least one more peak wavelength than the first spectrum, and whereinthe first light source supplies, to the plant, light of the first lightpattern and the second light source supplies, to the plant, light of thesecond light pattern.
 11. The plant cultivation device of claim 10,wherein the first light source comprises a plurality of the first lightemitters and a plurality of second light emitters, and a compositionratio of the plurality of first light emitters and the plurality ofsecond light emitters differ.
 12. The plant cultivation device of claim10, wherein the controller controls the first light source and thesecond light source individually.
 13. The plant cultivation device ofclaim 10, wherein the controller controls operation of the first lightsource and second light source wirelessly.
 14. The plant cultivationdevice of claim 10, wherein the plurality of third light emitters isfurther configured to provide to the plant the third light correlated toincrease a content of an active ingredient in the plant, wherein theactive ingredient comprises at least one of chlorophylls, flavonoids,anthocyanins, chlorogenic acids, sesquiterpene lactones, and phenoliccompounds.
 15. The plant cultivation device of claim 14, wherein thecontroller is further configured to control the first light emitter, thesecond light emitter, and the plurality of third light emitters suchthat the light of the first light pattern is customized to a type ofseeds of the plant.
 16. A plant cultivation light module comprising: afirst light source comprising a plurality of first light emittersconfigured to emit first light and a plurality of second light emittersconfigured to emit second light having a longer peak wavelength than thefirst light, a second light source comprising a plurality of third lightemitters configured to emit third light having a shorter peak wavelengthto the first light; and a controller configured to control the pluralityof first light emitters, the plurality of second light emitters, and theplurality of third light emitters such that a first light pattern and asecond light pattern are provided, wherein the first light source andthe second light source further comprise a first semiconductor layer, asecond semiconductor layer, and an active layer, the active layer beingdisposed on the first semiconductor layer to emit a light having aspecific wavelength due to a band gap difference in an energy banddepending on a material used to form the active layer, wherein the firstlight pattern provides a first spectrum and the second light patternprovides a second spectrum having at least one more peak wavelength thanthe first spectrum, and wherein a composition ratio of the plurality offirst light emitters and the plurality of second light emitters differ.17. The plant cultivation light module of claim 16, wherein thecontroller controls the first light source and the second light sourceindividually.
 18. The plant cultivation light module of claim 16,wherein the controller controls operation of the first light source andsecond light source wirelessly.
 19. The plant cultivation light moduleof claim 16, wherein the plurality of third light emitters provides tothe plant the third light correlated to increase a content of an activeingredient in the plant, wherein the active ingredient comprises atleast one of chlorophylls, flavonoids, anthocyanins, chlorogenic acids,sesquiterpene lactones, and phenolic compounds.
 20. The plantcultivation light module of claim 19, wherein the composition ratio isadjusted such that the first light pattern, the second light pattern orboth are customized to a type of the plant.